1. Field of the Invention
This invention relates to a shoe having a sole filler provided in part by an insole and a method of making the shoe.
2. Brief Description of the Prior Art
In the manufacture of footwear, it is known to mold soles of rubber, polyvinyl chloride (PVC), polyurethane or other elastomers either directly to the shoe upper or to a welt which has been stitched to the shoe upper. Typical examples of such prior arts are set forth in the patents of Auberry et al. U.S. Pat. Nos. 3,965,517 and 3,758,903. While footwear of the type set forth in the above mentioned prior art operates in satisfactory manner for the purposes intended, when a rigid sole is required, the sole tends to be heavy, relatively hard and does not provide good thermal insulation. On the other hand, when rigidity is not required and properties other than those inherent in rigid soles are desired, foamed soles have been utilized. However, the prior art has not provided the combination of sole rigidity with sole softness or cushioning, light weight and good thermal insulation properties all in a single shoe.
In accordance with the present invention, there is provided a sole and method of making same which can provide the rigidity of the prior art rigid soles and still provide the other above noted desirable properties not inherent in rigid soles.
Briefly, in accordance with the present invention, there is provided a shoe having an upper and a sole secured to the upper, either directly or through a welt. The sole is preferably rigid and can have any desired properties, includes a hollow sole interior section extending from the toe region to and under the ball and entire heel region into which is secured a preferably premolded insole of a material having the desired properties, preferably a relatively soft foam which provides cushioning, light weight and thermal insulation. The insole includes a cradled lip extending over the remaining interior portion of the sole which provides added comfort and thermal insulation. The insole can be cradled as opposed to being flat to better conform to the contour of the wearer""s foot. The insole is secured to the sole by means of adhesive, such as an epoxy, or by mating members in the sole and insole, such as a tongue and groove, the tongue preferably being a portion of the insole and the groove being premolded into the sole. The tongue and groove insole embodiment can be made easily removable for the purpose of, for example, drying, airing or cleaning thereof.
The shoe with sole in accordance with the present invention is fabricated by placing an upper on a last in standard manner, placing a mold insert in the shape of the hollow sole interior section on the last bottom, the mold insert preferably being a permanent part of the last bottom, bringing the sole plate or mold for the sole and the last with upper thereon together in standard manner and then forming the sole in the sole plate. The sole will adhere to the welt or the upper as in the prior art. However, there will be a cavity in the sole in the shape of the mold insert, this cavity being the hollow sole interior section. The sole will also contain grooves in the event the insole is to be mated therewith.
An insole is preferably premolded and is preferably of a material different from that of the sole. This insole has a bottom portion which is the same shape as the hollow sole interior section and fits therein, the remaining portion of the insole, or lip, lying above the sole and resting thereover. After removal of the upper from the last with mold insert, the insole is secured to the sole either by an adhesive, preferably an epoxy, or by tongues formed in the bottom portion thereof which mate with the grooves in the sole, thereby providing a removable insole. Of course, the tongues and grooves can be reversed.
As an alternative, the mold insert can be removed from the last after formation of the sole and a second material can be inserted into the hollow sole interior section. In this case, the last without the mold insert and the sole form the mold cavity for the second material.
The sole is formed from any of the known prior art moldable sole materials, all of which are well known. Preferable sole materials are thermoplastic materials, preferably PVC, and rubber. Preferable insole materials are foams, preferably polyurethane and other blown materials.